For tumors and metastases to grow, they require a supply of blood to provide them with oxygen and nutrients. The blood vessels that surround tumors exhibit an uncontrolled and unnaturally fast growth (angiogenesis) rendering them more permeable for particles than normal vessels are. Furthermore, tumor tissue often has limited lymphatic drainage, which causes retention of particles compared to healthy tissue. Spago Nanomedical´s proprietary nanoparticles are optimized to make use of this Enhanced Permeability and Retention (EPR) effect. Following administration to the patient by injection, the polymeric particles will circulate in the bloodstream until they reach the tumor site. The nanoparticles will successively leave the blood vessels through the pores in the vessel walls (extravasation) and accumulate in the tumor tissue. In this way, the particle concentration in the tumor is built up over a few hours, enabling physiological targeting independent of molecular interaction with tumor cells.
Targeting by the EPR-effect with Spago Nanomedical´s nanoparticles has been clinically validated in patients with breast cancer, as well as in several different preclinical cancers models.
Spago Nanomedical’s technology platform is based on polymeric nanoparticles with excellent properties for binding of medically functional elements and accumulation in tissues positive for the EPR-effect. This provides for physiological targeting of particles with inherent diagnostic or therapeutic efficacy, i.e. functional nanoparticles.
The composition and size of the nanoparticles is key to preferential targeting to diseased tissue. The organophosphosilane core is tailored to bind elements that are either suited for diagnostics or therapy; Binding the paramagnetic manganese ion (Mn2+) provide for excellent contrast in magnetic resonance imaging (MRI), whereas the clinically validated radioisotope lutetium 177 (177Lu) provide opportunity for radionuclide therapy in different cancer indications. The outer particle layer consists of a proprietary PEG-coating which contributes size- and circulation properties for optimal targeting as well as avoidance of immunogenic reactions.
